1. Field of the Invention
The present invention is directed to an improved head bail apparatus for use in a livestock restraining device which may include a cattle crush or cattle squeeze. The head bail apparatus is also known as a head restraint, a head gate or a neck yoke.
2. Description of the Related Art
Livestock animals such as cattle need to be periodically restrained to enable the animal to be marked, examined or treated. It is well known to use a livestock restraining device and an example of such a device is a cattle crush or cattle squeeze. The device traps the animal by the neck and does so by a head bail assembly or head gate assembly. The assembly comprises a pair of neck bars which operate between an open “free” position and a holding position. The neck bars can be supported on the side of gates (e.g. baulk gates) which move between the free and holding positions. The movement can be a sliding movement or a swinging movement. The animal is held in position between the neck bars.
It is important that the neck bars hold the animal securely enough to prevent the animal from struggling free. Thus it is known to squeeze the neck bars against the animals neck almost to a choking point and then to lock the bars in position. The initial trapping is achieved using a manual lever on the side of the bail assembly which is lifted up and down to open and close the gates. A toothed ratchet assembly is provided to enable the gates to be locked at various spaced apart positions depending on the size of the animal to be trapped. A disadvantage with this system is that the gates can only be locked at certain positions which correspond to the spacing of the teeth in the ratchet mechanism. Thus is it possible for one spacing to be too large and not able to properly restrain an animal while the next spacing may choke the animal.
An attempt has been made to use strong springs to hold the neck bars against an animal; however if the spring tension is too low, the animal may struggle free and if the spring tension is too high, the animal may choke. Pulleys and chains or wires connected to a spring to hold the animal have also been tried but may suffer from the same disadvantages.
Other devices may be expensive or require powerful motors for operation.
Pneumatic rams may be known to operate the neck bars, but cannot normally hold the captured animal unless the bore size is large enough to create forces which are both dangerous in operation and impractical in use because of the large volumes of compressed air required.
Adjustable locks on the neck bars or head bail doors may be difficult, impracticable and possibly dangerous to use especially if a large horned animal is being held.
Thus there would be an advantage if it were possible to provide a head bail apparatus which could temporarily lock the neck bars at any desired position as opposed to discrete spaced apart positions and which could overcome at least some of the above disadvantages or provide a useful or commercial choice in the marketplace.
Any references to methods, apparatus or documents of the prior art are not to be taken as constituting any evidence or admission that they formed, or form part of the common general knowledge.